"One who is subservient to the tongue and who thus goes here and there, devoted to the genitals and the belly, cannot attain Kṛṣṇa."
(Sri Caitanya Caritamrta-------translation).

"O Lord! This material body is a lump of ignorance, and the senses are a network of paths leading to death. Somehow or other we have fallen into the ocean of material sense enjoyment, and of all the senses the tongue is the most voracious and uncontrollable. It is very difficult to conquer the tongue in this world, but You, dear Kṛṣṇa, are very kind to us. You have sent this nice prasāda to help us conquer the tongue; therefore let us take this prasāda to our full satisfaction and glorify Your Lordships Śrī Śrī Rādhā and Kṛṣṇa and in love call for the help of Lord Caitanya and Prabhu Nityānanda." There are six kinds of rasas (tastes), and if one is agitated by any one of them, he becomes controlled by the urges of the tongue. Some persons are attracted to the eating of meat, fish, crabs, eggs and other things produced by semina and blood and eaten in the form of dead bodies. Others are attracted by eating vegetables, creepers, spinach or milk products, but all for the satisfaction of the tongue's demands. Such eating for sense gratification—including the use of extra quantities of spices like chili and tamarind—is to be given up by Kṛṣṇa conscious persons. The use of pan, haritakī, betel nuts, various spices used in pan-making, tobacco, LSD, marijuana, opium, liquor, coffee and tea is indulged in to fulfill illicit demands. If we can practice accepting only remnants of food offered to Kṛṣṇa, it is possible to get free from māyā's victimization. Vegetables, grains, fruits, milk products and water are proper foods to offer to the Lord, as Lord Kṛṣṇa Himself prescribes. However, if one accepts prasāda only because of its palatable taste and thus eats too much, he also falls prey to trying to satisfy the demands of the tongue. Śrī Caitanya Mahāprabhu taught us to avoid very palatable dishes even while eating prasāda. If we offer palatable dishes to the Deity with the intention of eating such nice food, we are involved in trying to satisfy the demands of the tongue. If we accept the invitation of a rich man with the idea of receiving palatable food, we are also trying to satisfy the demands of the tongue. In Caitanya-caritāmṛta (CC.3:6:227) it is stated:
jihvāra lālase yei iti-uti dhāya
śiśnodara-parāyaṇa kṛṣṇa nāhi pāya
"That person who runs here and there seeking to gratify his palate and who is always attached to the desires of his stomach and genitals is unable to attain Kṛṣṇa."

As stated before, the tongue, belly and genitals are all situated in a straight line, and they fall in the same category. Lord Caitanya has said, bhāla nā khāibe āra bhāla nā paribe: "Do not dress luxuriously and do not eat delicious foodstuffs." (CC.3:6:236)

Those who suffer from diseases of the stomach must be unable to control the urges of the belly, at least according to this analysis. When we desire to eat more than necessary we automatically create many inconveniences in life. However, if we observe fasting days like Ekādaśī and Janmāṣṭamī, we can restrain the demands of the belly.

(Nectar of Instruction).